I am trying to connect to the selectionChanged signal of a QTreeView using PyQt. I have done this in the past (for a QTableView) and was successful. But now I cannot get similar code to work.
In the following code example, I successfully connect to the expanded and collapsed signals, but not to the selectionChanged or activated signals. Could someone tell me what I am doing wrong? Thanks.
from PyQt4 import QtGui
from PyQt4 import QtCore
################################################################################
class ShaderDefTreeView(QtGui.QTreeView):
"""
Overrides the QTreeView to handle keypress events.
"""
#---------------------------------------------------------------------------
def __init__(self, parent=None):
"""
Constructor for the ShaderDefTreeView class.
"""
super(ShaderDefTreeView, self).__init__(parent)
#listen to the selectionChanged signal
print "Connecting"
#whenever the selection changes, let the data model know
self.connect(self,
QtCore.SIGNAL("selectionChanged(QItemSelection&, QItemSelection&)"),
self.store_current_selection)
self.connect(self, QtCore.SIGNAL("activated(const QModelIndex &)"),
self.activated)
self.connect(self, QtCore.SIGNAL("collapsed(const QModelIndex &)"),
self.collapsed)
self.connect(self, QtCore.SIGNAL("expanded(const QModelIndex &)"),
self.expanded)
#---------------------------------------------------------------------------
def store_current_selection(self, newSelection, oldSelection):
print "changed"
#self.model().selection_changed(newSelection)
#---------------------------------------------------------------------------
def expanded(self, newSelection):
print "expanded"
#---------------------------------------------------------------------------
def collapsed(self, newSelection):
print "collapsed"
#---------------------------------------------------------------------------
def activated(self, newSelection):
print "activated"
Ok, figured it out (mostly by accident).
Since I was making the connections in the init but only setting the model for this QTreeView later, there was no valid selectionModel in place.
In order to make it work I had to make two changes:
1) The emitting object had to be changed to be the QTreeView's selectionModel. I don't know why, but some (rare) examples on the web suggested that this might be the case
and
2) I had to override the setModel method of the QTreeView such that it calls the superclass' setModel method and then makes the connections afterwards.
So the new code looks like this:
class ShaderDefTreeView(QtGui.QTreeView):
"""
Overrides the QTreeView to handle keypress events.
"""
#---------------------------------------------------------------------------
def __init__(self, parent=None):
"""
Constructor for the ShaderDefTreeView class.
"""
super(ShaderDefTreeView, self).__init__(parent)
#---------------------------------------------------------------------------
def setModel(self, model):
super(ShaderDefTreeView, self).setModel(model)
self.connect(self.selectionModel(),
QtCore.SIGNAL("selectionChanged(QItemSelection, QItemSelection)"),
self.store_current_selection)
#---------------------------------------------------------------------------
def store_current_selection(self, newSelection, oldSelection):
print "changed"